Antiseptic mouthwashes: in vitro antibacterial activity

Area of Science:

• Oral microbiology
• Antimicrobial susceptibility testing

Background:

• Mouthwashes are commonly used alongside brushing to enhance oral hygiene and prevent diseases.
• Mutans streptococci (MS) are key pathogens in dental caries development.

Purpose of the Study:

• To compare the in vitro antibacterial efficacy of three mouthwashes with different active ingredients against mutans streptococci.
• To determine the Maximum Inhibitory Dilution (MID) for Periogard®, Cepacol®, and Plax® Fresh Mint against clinical isolates of MS.

Main Methods:

• Antibacterial activity was assessed using a serial two-fold dilution method in 96-well microtiter plates.
• Thirty-six clinical isolates of mutans streptococci were exposed to dilutions of each mouthwash.
• Maximum Inhibitory Dilution (MID) was determined after 48 hours of microaerobic incubation at 37°C.

Main Results:

• Periogard® (containing chlorhexidine) and Cepacol® (containing cetylpyridinium chloride) exhibited a Maximum Inhibitory Dilution (MID) of 1/320.
• Plax® Fresh Mint (containing triclosan) showed a significantly lower MID of 1/20.
• Statistical analysis confirmed that the MID of Periogard® was not significantly different from Cepacol® but was significantly higher than Plax® (p<0.05).

Conclusions:

• Antiseptic mouthwashes containing chlorhexidine and cetylpyridinium chloride demonstrate superior in vitro antibacterial activity against mutans streptococci compared to triclosan-based mouthwash.
• The findings suggest that Periogard® and Cepacol® are more effective in inhibiting MS growth at higher dilutions.
• This study provides valuable data for selecting mouthwashes with enhanced antimicrobial properties for oral disease prevention.